The prior art discloses various golf clubs having roller means on the ground-engaging face to facilitate movement of the club over the ground, such as U.S. Pat. Nos. 2,426,274, 3,044,781, 3,199,873 3,680,868 and 4,535,992. The advantages of a roller means are that it will tend to cause the club to move in a line defined by the direction of rotation of the roller and that it will maintain a minimum distance between the club head and the playing or putting surface and thus permit contact of the head with a hard surface such as frozen ground or, for indoor practicing for example, concrete or wood. Reducing the drag between the club and the ground also reduces the tendency for the club head to be deflected or to turn about the shaft and thus to be skewed when it strikes the ball as for example when the toe of the club brushes the ground, which tends to rotate the head about the shaft.
Because a golf putter sanctioned for tournament play cannot have movable parts, clubs with rollers have generally been designated for training or practice purposes and not for play. Training systems have also been offered in which there is used a set of two putters including a training putter having roller means and a playing putter from which the roller means is eliminated. ideally of course both the training clubs and the playing clubs should be the same or as nearly alike as possible.
There is also in the prior art various disclosures of golf clubs with markings on the head for aligning the head with the ball and for indicating the direction of the swing, such as U.S. Pat. Nos. 3,199,873 and 3,680,868 mentioned above as well as U.S. Pat. Nos. 2,781,197 and 2,865,635.